Updated on 2024-06-18 GMT+08:00

Truncating an Object (SDK for Java)

Function

This API truncates an object in the PFS.

If you have any questions during development, post them on the Issues page of GitHub.

Restrictions

Method

obsClient.truncateObject(TruncateObjectRequest request)

Request Parameters

Table 1 List of request parameters

Parameter

Type

Mandatory (Yes/No)

Description

request

TruncateObjectRequest

Yes

Explanation:

Request parameters for truncating an object. For details, see Table 2.

Table 2 TruncateObjectRequest

Parameter

Type

Mandatory (Yes/No)

Description

bucketName

String

Yes

Explanation:

Bucket name.

Restrictions:

  • A bucket name must be unique across all accounts and regions.
  • A bucket name:
    • Must be 3 to 63 characters long and start with a digit or letter. Lowercase letters, digits, hyphens (-), and periods (.) are allowed.
    • Cannot be formatted as an IP address.
    • Cannot start or end with a hyphen (-) or period (.).
    • Cannot contain two consecutive periods (..), for example, my..bucket.
    • Cannot contain periods (.) and hyphens (-) adjacent to each other, for example, my-.bucket or my.-bucket.
  • If you repeatedly create buckets of the same name in the same region, no error will be reported and the bucket attributes comply with those set in the first creation request.

Default value:

None

objectKey

String

Yes

Explanation:

Name of a file object. An object is uniquely identified by an object name in a bucket. An object name is a complete path that does not contain the bucket name.

For example, if the address for accessing the object is examplebucket.obs.ap-southeast-1.myhuaweicloud.com/folder/test.txt, the object name is folder/test.txt.

Value range:

The value must contain 1 to 1,024 characters.

Default value:

None

newLength

long

Yes

Explanation:

Size of the file after being truncated.

Default value:

None

Responses

Table 3 TruncateObjectResult

Parameter

Type

Description

statusCode

int

Explanation:

HTTP status code.

Value range:

A status code is a group of digits that can be 2xx (indicating successes) or 4xx or 5xx (indicating errors). It indicates the status of a response.

For more information, see Status Code.

Default value:

None

responseHeaders

Map<String, Object>

Explanation:

Response header list, composed of tuples. In a tuple, the String key indicates the name of the header, and the Object value indicates the value of the header.

Default value:

None

Code Examples

This example truncates object objectname in parallel file system examplebucket to 1024L.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.TruncateObjectRequest;
import com.obs.services.model.TruncateObjectResult;
public class TruncateObject001 {
    public static void main(String[] args) {
        // Obtain an AK/SK pair using environment variables or import the AK/SK pair in other ways. Using hard coding may result in leakage.
        // Obtain an AK/SK pair on the management console.
        String ak = System.getenv("ACCESS_KEY_ID");
        String sk = System.getenv("SECRET_ACCESS_KEY_ID");
        // (Optional) If you are using a temporary AK/SK pair and a security token to access OBS, you are advised not to use hard coding, which may result in information leakage.
        // Obtain an AK/SK pair and a security token using environment variables or import them in other ways.
        // String securityToken = System.getenv("SECURITY_TOKEN");
        // Enter the endpoint corresponding to the bucket. CN-Hong Kong is used here as an example. Replace it with the one in your actual situation.
        String endPoint = "https://obs.ap-southeast-1.myhuaweicloud.com";
        // Obtain an endpoint using environment variables or import it in other ways.
        //String endPoint = System.getenv("ENDPOINT");
        
        // Create an ObsClient instance.
        // Use the permanent AK/SK pair to initialize the client.
        ObsClient obsClient = new ObsClient(ak, sk,endPoint);
        // Use the temporary AK/SK pair and security token to initialize the client.
        // ObsClient obsClient = new ObsClient(ak, sk, securityToken, endPoint);

        try {
            // Truncate an object.
            TruncateObjectRequest request = new TruncateObjectRequest();
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            request.setNewLength(1024L);
            TruncateObjectResult result = obsClient.truncateObject(request);
            System.out.println("truncateObject successfully");
            System.out.println("HTTP Code: " + result.getStatusCode());
        } catch (ObsException e) {
            System.out.println("truncateObject failed");
            // Request failed. Print the HTTP status code.
            System.out.println("HTTP Code:" + e.getResponseCode());
            // Request failed. Print the server-side error code.
            System.out.println("Error Code:" + e.getErrorCode());
            // Request failed. Print the error details.
            System.out.println("Error Message:" + e.getErrorMessage());
            // Request failed. Print the request ID.
            System.out.println("Request ID:" + e.getErrorRequestId());
            System.out.println("Host ID:" + e.getErrorHostId());
            e.printStackTrace();
        } catch (Exception e) {
            System.out.println("truncateObject failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}